Certain refrigerator appliances include sealed systems for cooling chilled chambers of the refrigerator appliance. The sealed systems generally include a compressor that generates compressed refrigerant during operation of the sealed system. The compressed refrigerant flows to an evaporator where heat exchange between the chilled chambers and the refrigerant cools the chilled chambers and food items located therein.
Recently, certain refrigerator appliances have included linear compressors for compressing refrigerant. Linear compressors generally include a piston and a driving coil. The driving coil receives a current that generates a force for sliding the piston forward and backward within a chamber. During motion of the piston within the chamber, the piston compresses refrigerant. However, friction between the piston and a wall of the chamber can negatively affect operation of the linear compressors if the piston is not suitably aligned within the chamber. In particular, friction losses due to rubbing of the piston against the wall of the chamber can negatively affect an efficiency of an associated refrigerator appliance.
The driving coil generally engages a magnet on a mover assembly of the linear compressor in order to reciprocate the piston within the chamber. The magnet is spaced apart from the driving coil by an air gap. In certain linear compressors, an additional air gap is provided at an opposite side of the magnet, e.g., between the magnet and an inner back iron of the linear compressor. However, multiple air gaps can negatively affect operation of the linear compressor by interrupting transmission of a magnetic field from the driving coil. In addition, maintaining a uniform air gap between the magnet and the driving coil and/or inner back iron can be difficult.
Accordingly, a linear compressor with features for limiting friction between a piston and a wall of a cylinder during operation of the linear compressor would be useful. In addition, a linear compressor with features for maintaining uniformity of an air gap between a magnet and a driving coil of the linear compressor would be useful. In particular, a linear compressor having only a single air gap would be useful.